you might want to create a Design preset or theme in PowerPoint. This will help you apply the same design to all slides at once, and you can also send the theme to anyone for use by them.

You can edit a PowerPoint template by adjusting its theme settings. Your options for editing templates look fairly similar whether you make them on the desktop or web ...

Microsoft PowerPoint allows you to combine two or more presentations with different theme templates. PowerPoint includes a Keep Source Formatting option that retains the template format for each ...

This post will show you how to switch to Dark Gray, White, Gray, Colorful, or Black themes in Word, Excel, PowerPoint ... change the current default theme to the desired theme of your choice.